Yan Sun is studying new fascinating ways of using microalgae in the bioremediation of oil pollution.

When Yan Sun, a doctoral student in environmental sciences, is fishing at Lake Vesijärvi in Lahti during her leisure time, she prepares the catch in Chinese style.

“The internal organs, especially the swim bladder, are the most delicious part. My Finnish friends are horrified by this and claim that you cannot eat the whole fish,” Yan says.

She assures us that the water in the Lake Vesijärvi is now amazingly clean and that in some places, even drinkable. In fact, the cleanliness of water is close to her heart. In her dissertation research, Yan Sun is examining how to make the bioremediation of oil pollution in bottom sediments more effective by relying on microalgae.

Microalgae comprise a large variety of floating algae and other photosynthesising organisms, most of which are unicellular. Using them in the bioremediation of oil and other pollution has been studied for decades. However, the research method has been quite straightforward: the microalgae absorb oil and also degrade it as they grow.

In her research, Yan presents a new logic for using microalgae. Their main task is no longer to absorb oil, but to produce oxygen.

“Most microorganisms that are good at degrading oil can only survive in oxygenous environments. However, bottom sediments are often anoxic, which means that oil degrades very slowly,” Yan explains.

When microalgae are added to the bottom sediments, their main task is to be there and by being there they convert an anoxic environment into an oxygenous environment.

This creates a beneficial self-perpetuating circle: the microalgae are photosynthesising organisms, which means that they use solar energy to convert carbon dioxide and water into sugar and oxygen. After this, aerobic microorganisms (microbes that base their metabolism on oxygen) absorb and degrade large amounts of oil and release carbon dioxide into the water. Microalgae will then convert this carbon dioxide back into oxygen in the photosynthesis process.

“By supporting microalgae, we will strengthen the natural oil degradation mechanism. This method is very environmentally friendly. You do not need to add chemicals to water that may be toxic to some species, or organisms that may cause chaos in the ecosystem in one way or another.”

Yan points out that microalgae-based bioremediation is also an excellent method from the perspective of the climate change.

“In photosynthesis, microalgae reduce the atmospheric release of carbon dioxide generated in oil biodegradation and they also absorb carbon dioxide from the atmosphere as they grow.”

Yan points out that even the best biodegrading organisms are quite slow at decomposing complex oil molecules. In an ideal situation, the oil will degrade completely into carbon dioxide. However, in most cases, the degradation will produce a slightly lighter and (usually) less toxic chemical.

Another factor hampering the use of microalgae in bottom sediments is that photosynthesis requires sunlight, which is, however, absent in the bottom mud of polluted sea areas.

In fact, as part of her dissertation research, Yan is planning new ways of improving the access of sunlight to the bottom of seas and lakes. She cannot, however, disclose the details of the mechanism, because there are plans to apply for a patent for the idea.

Yan spent some time as an exchange student at the Tampere University of Technology in 2010 as she was studying for a bachelor’s degree in environmental sciences at the Guangzhou University. Two years later, she moved to Lahti to study for a master’s degree.

“I had already calculated the results in my head, when the Finnish students were still working on the exercises with their pocket calculators.” According to Yan, in China, mathematics is studied much more intensively at the upper level of comprehensive school and at upper secondary level than in Finland.

However, at university level, the situation is the opposite. For a mathematically gifted student like Yan, taking the bachelor’s degree in China was easy. Everything took place in the classroom: students only needed to read textbooks, because they contained all the knowledge, and to do calculation exercises.

“In Finland, I had to start doing things myself. It was a shock. I had to prepare projects, find scientific articles and read them, and write lots of text. It took a long time before I got used to this system. However, in the end I did.”

Yan has particularly fond memories of the laboratory course during her master’s studies. Students collected soil, water and snow samples in a city, suburb and a rural area and compared the amount of pollutants in different locations.

“The professor in charge of the course published an article based on the research carried out by the students. In courses like this, China lags well behind Finland.”

Text: Antti Kivimäki
Photos: Pekka Hannila

Sun Yan, Master of Arts, received a grant of 24,000 euros from the Päijät-Häme Regional Fund in May. The grant is intended for a dissertation in which she will examine the use of microalgae in the bioremediation of oil in water and land environments in the Baltic region.

The medieval village of Mankby was deserted in the sixteenth century. A team of researchers examined the history of the unique site in a project that spanned several years.

The story of Mankby unfolded gradually. The village turned out to have been a diverse whole, and the results of the project were surprising.

– At the very beginning, we discovered a fossilised medieval village, with most of the buildings constructed during its final stage more or less visible to the naked eye. Excavations provided us with access to its earlier stages. There are not many fossilised villages of this type in Finland, and it is already safe to say that an equally large and well-preserved medieval village can hardly be found anywhere else in Finland, says Georg Haggrén, an adjunct professor of historical archaeology, about Mankby, a village that used to be located in what is now Espoo.

Haggrén and his team have been examining Mankby since 2007. A book, Mankby – A deserted medieval village on the coast of southern Finland, was published as a result of the long process in May 2016.

The oldest buildings discovered in Mankby are from the thirteenth century. By Finnish standards, Mankby was a large village, with its eight houses and around 50 inhabitants. All of the houses were relocated in 1556, when Espoo Manor was established. Some of the buildings were transferred by peasants, while others were used by the Crown for purposes related to the manor.

– This means that there is a sense in which time stopped for Mankby 500 years ago. In some respects, land use has been practically non-existent since then, which makes Mankby a unique site, says Haggrén.

– There is very little information about medieval Finland. Archaeology provides us with better access to daily life than written sources, which focus more on administration. There is more information about the period beginning in the seventeenth century, but Mankby had already been abandoned at that point.

However, written material has been discovered about the very final stages of the village, and this material indicates the number of houses and also provides some information about farming, mostly consisting of the names of farmers.

Researcher Tarja Knuutinen was in charge of the excavations in the lower part of the village. This area covered around 100 square metres in the eastern part of the village and included sites of buildings, ancient fields and roadbed.

– I examined a building that was only slightly visible above the ground when we started. It was a building from the final stages of the village that had probably been taken down when the village was abandoned. In addition, we discovered earlier structures dating back as far as the fourteenth century.

According to Knuutinen, the building from the early sixteenth century is very similar to later smoke cottages. It is part of a building tradition that continued almost until our time. Another building examined in Mankby turned out to be a double cottage – that is, a markedly larger house. According to the researchers, it was not the home of an ordinary peasant, but the home of a member of the rälssi class, which was exempt from taxes and enjoyed many other privileges.

The development of the village and its layers can be seen in its lower part: the village was first used for cultivation and then for construction.

– The fossilised fields have now been dated to the fourteenth century, and their cultivation may have continued until the early fifteenth century. In terms of research, they constitute an interesting whole, as there are not many similar fields located in the middle of a village. In Mankby, we have gained access to a system of fields and its ditches and foundations.

The artefacts discovered in Mankby are varied and indicate an active culture of trading that provided even peasants with items from as far as Central Europe. These artefacts include fragments of glass goblets, three-legged cauldrons made of red clay and jugs made of stone clay, as well as pieces of horse accessories, such as stirrups, and jewellery and buckles and other items related to clothing.

– From the very beginning, we found an exceptionally large number of knives: sheath knives used for daily work and eating, as well as fine table knives that reached Finland along with influences of Central European culinary culture in the fifteenth and sixteenth centuries. These influences clearly had found their way to Mankby as well, says Elina Terävä, who was responsible for the examination of artefacts.

The varied artefacts also indicate that people living in modest homes had items that are not traditionally associated with the austerity of peasant life. This came as a surprise to the researchers as well.

– The artefacts are quite fine. We discovered a surprisingly large amount of imported goods, which is a sign of trading. Small ornamental items made of iron, for example, indicate that life was not only about necessities. The people wanted a little luxury, which was provided by items used in Central Europe, for example.

Photo: The knives attracted the researchers’ attention. With its length of more than 20 centimetres, this knife was exceptionally large, as well as being unusually ornate. The knives were decorated using bronze and bone, among other materials.

Georg Haggrén, PhD, was awarded a grant of EUR 55,000 by the Finnish Cultural Foundation in 2014 for a research project on the medieval village of Mankby in Espoo and the publication of its results.

The image of the taciturn Finns is a much-repeated stereotype that is still common. At the same time, Finns are automatically subject to being compared with other nationalities.

“However, no one has actually studied the nature of this taciturnity,” says Anna Vatanen, who is a postdoctoral researcher at the University of Helsinki. “In what situations are Finns reticent and compared to whom?” Vatanen decided to take on the task herself.

Vatanen looks at how people who are acquainted with each other behave in natural interaction situations. She studies how they react to moments of silence during a conversation and how they create such moments: what marks the beginning and the end of silence and what happens in between. Is the silence natural or awkward? Do the persons involved feel the need to busy themselves with something else during the silence? Vatanen bases her analysis on videotaped conversations.

Vatanen looks for pauses and repetitive patterns in the pauses. Her aim is to find any general strategies and relate them to the common suppositions about Finnish taciturnity and findings from studies in other languages.

Moments of silence

Although it is early days, Vatanen already suspects that there is something unique to the way Finns relate to silence. Earlier research has shown that pauses occur even among English-speakers. However, during these pauses, the parties typically focus on something else, like petting a dog or fetching a book. In conversations between Finns, there are moments when nothing happens at all.

“They just remain there, quite relaxed,” Vatanen explains.

“The most interesting thing is not necessarily how long the pause is, but what happens during it.”

Vatanen’s research material includes discussions while eating breakfast, driving in a car, playing board games and visiting a friend. Naturally, some pauses occur when a speaker focuses on something else, such as the next move in the game. But, as Vatanen points out, such situations do not always require everybody else to stop talking.

“Even a couple of seconds of silence may feel like a long time. If there are many such moments and they don’t seem awkward, it probably means that the people involved are alright with them.”

What is silence?

“As a matter of fact, ‘silence’ only means that nobody is speaking in a situation,” says Vatanen. “But there are other kinds of interaction, such as nods and looks, which makes silence slightly misleading.”

It is also a matter of how people manifest their connections. Words are not always required; just being there is sometimes enough.

“Maybe it’s characteristic of Finnish-speakers to refrain from saying anything at all. It may be a normal way of being together. On the other hand, even if Finns have a different attitude to silence than other nationalities, it does not mean that Finns are always, or in general, ‘taciturn’. Furthermore, you mustn’t treat ‘Finns’ as a homogeneous group with just one, common way of doing things.”

In spring, Vatanen will travel to Australia to work with her colleagues there. She is eager to learn about the Australian researchers’ views on the subject and if they see it as something strange or anomalous.

“I don’t think I will be able to establish where the notion of the taciturn Finns originates, but I hope and believe I will be able to reveal something about the reality behind the stereotype.”

In 2016, the Finnish Cultural Foundation awarded Anna Vatanen, PhD, a grant for post-doctoral research on the theme of taciturn Finns.

Professor Hanna Kokko was awarded an award for outstanding cultural achievement at Cultural Foundations Annual Gala on 27 February. The award was given to a researcher of courtship and evolution and the defender of the diversity of life.

Kokko specialises in theoretical ecology and evolutionary biology. She took her matriculation examination in the German School in Helsinki in 1990 and graduated as a Master of Science (tech.) from the Helsinki University of Technology. She continued her studies at the University of Helsinki, writing her doctoral dissertation on the evolution of sexual choice and courtship in 1997.

Hanna Kokko is truly cosmopolitan scientist. She has worked as a post doc researcher at the University of Cambridge and at the University of Glasgow and as senior assistant at the University of Jyväskylä. In 2004 she was appointed professor of animal ecology at the University of Helsinki. Then she was appointed as an Australian Laureate Fellow, considered to be the country’s most distinguished scientific post. Now she has returned to Europe, taking up the post of a professor in evolutionary biology at the University of Zurich.

Kokko has published more than 200 scientific articles, books and works that are also intended for the public at large. The book Kutistuva turska (Shrinking cod), written by Hanna Kokko and Katja Bargum in a lucid and informative style, received the State Award for Public Information in 2009. The articles and publications of Kokko are frequently cited and she often appears as a speaker at events around the world. This is because she is able to present complex mathematical formulas in a manner that all audiences can understand.

Hanna Kokko studies the interactive relationships between individuals and groups. She is particularly interested in situations in which the good of the individual is in conflict with the good of the population, species or a community. In economics, this is called the tragedy of the commons, but it also affects nearly all interactive biological relationships at cellular level and in communities alike. In recent years, Hanna Kokko has studied phenomena such as cancer from this perspective. Hanna Kokko emphasises that we can only save our planet by preserving the diversity of species and by ensuring the existence of differences in nature.

It is as if a woman is whispering “OK” amidst the noise. Unto K. Laine, professor of acoustics at Aalto University, is playing a recording made in North Karelia during a display of the Aurora Borealis.

According to Laine, the sounds produced by the Northern Lights may also recall a waterfall, crackling or banging. For centuries, people around the world have told stories of the sounds, but many scientists remain sceptical.

– As recently as fifteen years ago, such stories were dismissed as products of the imagination, Laine explains. He decided to look into the subject. After spending hundreds of nights making recordings, Laine is probably the only person in the world to document the sounds of the Aurora Borealis.

Laine is the first acoustics expert to study the phenomenon, and he believes that this has been crucial to his success. He has built much of the equipment himself, and he needs hypersensitive microphones. Laine uses three microphones so that he can determine the direction accurately. The site must be open and very quiet.

– Picking the sounds is like hitting the jackpot. It must be dead calm and not too humid, and there must be a real show going on in the sky.

Laine started studying the phenomenon in the year 2000, and his first successful recording followed shortly after that. In April that year, one of his students phoned and asked him to look out of the window.

– There was a fantastic light show going on. There was no time to waste, says Laine, recalling the situation.

He grabbed his recording equipment and soon found himself standing in the freezing cold and listening to the crackle with a cheap microphone.

– That prompted me to buy better equipment.

How can the sounds of the Aurora Borealis still be a source of controversy? Laine, too, is puzzled by this.

– The Northern Lights have inspired fear all around the world, and this may still be the case.

The fact that the sounds have been dismissed as imaginary is one reason why Laine started studying the subject. Many people have been reluctant to talk about the sounds that they have heard because they are afraid of being branded as crazy.

– I have read stories of people that had heard these sounds and experienced an ethical awakening. I thought that maybe these people are right and have simply been unfairly derided. I felt that I had to take a closer look at the subject.

The physical origin of the phenomenon remains a mystery. Laine believes that as the aurora is moving, the electromagnetic field also changes and triggers off a phenomenon that creates sounds at altitudes of less than 100 metres.

Laine is now planning to make new recordings, and he is checking the old ones. He hopes that one day computers will be able to pick the right sounds automatically from the recordings. Ultimately, findings by independent research groups are also needed as the final proof.

However, Laine has already convinced many of his colleagues. In summer 2014, a research team from Northern Ireland studying meteorite sounds contacted Laine and expressed its willingness to cooperate on the subject. As meteors burn up at an altitude of 20 kilometres, the sounds produced by them should not be audible. However, meteor sounds have been recorded and they may originate in the same manner as the sounds produced by the Northern Lights.